Central igniter for rotatable combustion chamber

ABSTRACT

In an engine of the type which has a combustion chamber which is rotatable in a stationary external support means and which has fore and aft ends, the combination comprising: an axially oriented elongated igniter which extends through the support means and the fore end of the combustion chamber; a plurality of fuel nozzles mounted in the fore end of the combustion chamber and rotatable therewith; the external support means having an annular main fuel passageway extending along and about the elongated igniter; and the fore end of the combustion chamber having fuel delivery passageways which extend between the main fuel passageway and the fuel nozzles.

United States Patent [191 Petersen Mar. 26, 1974 CENTRAL IGNITER FOR ROTATABLE COMBUSTION CHAMBER [75] Inventor: Donald J. Petersen, Highland Heights, Ohio [22] Filed: Nov. 22, 1972 [21] Appl. No.: 308,904

[56] References Cited UNITED STATES PATENTS 2,518,881 8/1950 Goddard 60/39.7 4 A 2,938,482 5/1960 Newborn et al.

2,977,755 4/1961 Geckler et a1. 60/39.46 X

. new ilsgllll 3,564,846 2/1971 Moore 60/39.82 H 3,267,672 8/1966 Craig et al. 60/256 X 2,667,032 1/1954 Boulet 2,836,958 6/1958 Ward 60/39.35

Primary ExaminerCarlton R. Croyle Assistant Examiner-Robert E. Garrett Attorney, Agent, or Firm-Richard S. Sciascia; Ervin F. Johnston [5 7] ABSTRACT In an engine of the type which has a combustion chamber which is rotatable in a stationary external support means and which has fore and aft ends, the combination comprising: an axially oriented elongated igniter which extends through the support means and the fore end of the combustion chamber; a plurality of fuel nozzles mounted in the fore end of the combustion chamber and rotatable therewith; the external support means having an annular main fuel passageway extending along and about the elongated igniter; and the fore end of the combustion chamber having fuel delivery passageways which extend between the main fuel passageway and the fuel nozzles.

3 Claims, 1 Drawing Figure CENTRAL IGNITER FOR ROTATABLE COMBUSTION CHAMBER STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefore.

BACKGROUND OF THE INVENTION The present invention relates to central ignition and fuel systems for a rotatable combustion chamber.

Prior art ignition and fuel delivery systems for rotatable combustion chambers have been somewhat cumbersome and unreliable. A common arrangement has been an igniter mounted laterally within the combustion chamber and a fuel spray nozzle located at a central position within one end of the chamber. In order to activate the igniter, annular brushes are located exterior to the end of the combustion chamber and contact slip rings are utilized for delivering electrical power. It is cumbersome for the brushes to rotate with the chamber. Also, it has been found that, in some applications, the brushes and slip rings are subject to corrosion which reduces reliability of the engine. This corrosion is especially prevalent when the combustion chamber is rotatable within a housing where water is circulated between the chamber and housing for cooling purposes.

SUMMARY OF THE INVENTION The present invention has overcome the problems associated with prior art arrangements by providing an axially oriented elongated igniter which extends through the fore end of the combustion chamber and a plurality of fuel nozzles which are mounted in the fore end of the chamber and which are rotatable therewith. The support means, upon which the combustion chamber rotates, has an annular main fuel passageway which extends along and about the elongated igniter, and the fore end of the combustion chamber has fuel delivery passageways which extend between the main fuel passageway and the fuel nozzles. In this manner, the igniter does not rotate with the combustion chamber and troublesome brushes and slip rings associated with prior art arrangements are eliminated.

STATEMENT OF OBJECTS OF INVENTION An object of the present invention is to overcome the aforementioned problems associated with prior art ignition and fuel delivery systems for rotatable combustion chambers.

Another object is to provide a highly reliable brushless igniter and fuel delivery system for a rotatable combustion chamber.

Other objects, advantages, and novel features of the invention will become apparent from the following detailed description of the invention, when considered in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a cross-sectional view of an exemplary engine having a rotatable combustion chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENT An exemplary embodiment, wherein a rotatable combustion chamber may be utilized, is illustrated in the drawing. The combustion chamber is illustrated at 10 and may have fore and aft ends 12 and 14. The combustion chamber 10 may be rotatably mounted within an external stationary housing 16 and supported by means of fore and aft bearing supports 18 and 20. The aft end of the combustion chamber 10 may be connected by a spline 22 to a shaft 24 which in turn supports a propeller 26. Another propeller 28 may be mounted to a tubular shaft 30 which in turn is fixed to a motor housing 31. These propellers are adapted for counterrotation by operation of a swash plate motor system (not shown) within the housing 31. The swash plate motor has pistons which are operated by hot gases which are discharged from the combustion chamber 10. These hot gases are delivered to the pistons by ports 32 in the aft end of the combustion chamber and by gas delivery passageways 34 within the housing 31. The swash plate system causes the shaft 24 to rotate in one direction and the housing 31 and tubular shaft 30 to rotate in an opposite position. This arrangement is a common propulsion system for the U.S. Navy Mark 46 torpedo.

An annular propellent charge 36 may be mounted within the combustion chamber 10 and a booster charge 38 may be mounted centrally within the propellent charge. The combustion chamber may be cooled by an annular water passageway 40 which is located be tween the chamber 10 and the housing 16.

An axially oriented elongated igniter 42 extends through the housing 16 and the fore end 12 of the combustion chamber. The extended end 43 of the igniter is disposed opposite the booster charge 38 within the combustion chamber. The igniter may have a tubular portion which terminates at the extended end, and this tubular portion may be filled with a pyrotechnic charge which is ignitable by an electric current. The opposite end 44 of the igniter may be adapted for connection to an electrical power source (not shown).

A plurality of fuel nozzles 46 may be radially mounted in the fore end 12 of the combustion chamber so as to be rotatable therewith. An annular main fuel passageway 48 may be located between the tubular portion of the igniter 42 and the housing 16. Fuel delivery to this passageway 48 may be through the fore end of the housing 16. The main fuel passageway 48 may be in communication with the fuel nozzles 46 by a plurality of fuel delivery passageways 50 in the fore end of the combustion chamber. These delivery passageways extend between the main fuel passageway 48 and the fuel nozzles 46. Mounted on the exterior of the housing 31 is a gear 52 which operates auxiliary equipment, such as a fuel pump (not shown) and water pump (not shown) which are started upon ignition of the booster charge 36.

OPERATION OF THE INVENTION An electrical current is applied at end 44 of the igniter which causes a pyrotechnic charge within the igniter 42 to blast the booster charge 38. The booster charge 38 in turn ignites the main propellant charge 36 which generates gases which are expelled through ports 32 thence through gas delivery passageways 34 to pistons in a swash plate engine (not shown). The gear 52 rotates which causes water to circulate through the annular passageway 40 and fuel to be delivered to the main fuel passageway 48. The fuel then passes through the passageways 50 and is discharged through fuel nozniter; zles 46 into the combustion chamber. The fuel is igthe igniter having a tubular portion which terminates nited within the combustion chamber by the burning at said extended end;

propellant 36 and the hot gase xi h gh h ports said tubular portion of the igniter being filled with a 32 to continue operation of the engine. 5 pyrotedmie harg and Obviously many modifications and variations of the an opposite d f the igniter being adapted for present invention are possible in the light of the above nection to an le tri al power source meansteachings. It is therefore to be understood that within A combination as l imed in claim 1 including the Scope of the pp Claims the invemion may be the aft end of the combustion chamber having ports practiced otherwise than as specifically described. f expelling gases generated within the combus- 1 claim: I tion chamber.

1. In an engme of the type whlch has a Combustlon 3. In an engine of the type which has a rotatable com- Chamber whlch ls 'F m a Stahonary external P bustion chamber which has fore and aft ends, the comport means and which has fore and aft ends, the combimatron comprising.

nation comprising: 1

an axially oriented elongated igniter which extends through the support means and the fore end of the combustion chamber;

a plurality of fuel nozzles mounted in the fore end of the combustion chamber and rotatable therewith;

said external support means having an annular main fuel passageway extending along and about the elongated igniter;

the fore end of the combustion chamber having fuel delivery passageways which extend between the main fuel passageways and the fuel nozzles and an annular propellant charge mounted within the combustion chamber;

a booster charge mounted centrally within the propellant charge opposite the extended end of the igan axially oriented elongated igniter which extends through the fore end of the combustion chamber; 7

a plurality of fuel nozzles mounted in the fore end of the combustion chamber and rotatable therewith;

an annular propellant charge mounted within the combustion chamber;

a booster charge mounted centrally within the propellant charge opposite the extended end of the igniter;

the aft end portion of the igniter containing a pyrotechnic charge; and

the forward end of the igniter being adapted for connection to an electrical power source means. 

1. In an engine of the type which has a combustion chamber which is rotatable in a stationary external support means and which has fore and aft ends, the combination comprising: an axially oriented elongated igniter which extends through the support means and the fore end of the combustion chamber; a plurality of fuel nozzles mounted in the fore end of the combustion chamber and rotatable therewith; said external support means having an annular main fuel passageway extending along and about the elongated igniter; the fore end of the combustion chamber having fuel delivery passageways which extend between the main fuel passageways and the fuel nozzles and an annular propellant charge mounted within the combustion chamber; a booster charge mounted centrally within the propellant charge opposite the extended end of the igniter; the igniter having a tubular portion which terminates at said extended end; said tubular portion of the igniter being filled with a pyrotechnic charge; and an opposite end of the igniter being adapted for connection to an electrical power source means.
 2. A combination as claimed in claim 1 including: the aft end of the combustion chamber having ports for expelling gases generated within the combustion chamber.
 3. In an engine of the type which has a rotatable combustion chamber which has fore and aft ends, the combination comprising: an axially oriented elongated igniter which extends through the fore end of the combustion chamber; a plurality of fuel nozzles mounted in the fore end of the combustion chamber and rotatable therewith; an annular propellant charge mounted within the combustion chamber; a booster charge mounted centrally within the propellant charge opposite the extended end of the igniter; the aft end portion of the igniter containing a pyrotechnic charge; and the forward end of the igniter being adapted for connection to an electrical power source means. 